The study was conducted 1. to examine the performance of aerobic bacteria in treating a pesticide industry effluent and to quantify the biodegradation in terms of bio-kinetic parameters at steady state and 2. to study the inhibition caused by the pesticide effluent on un-acclimated ethanol enriched aerobic culture. The performance of the treatment was monitored based on total organic carbon (TOC), total nitrogen (TN), and sulfate removal at different SRTs. Highest COD removal of 80% was observed for SRTs greater than 8-day. The steady state kinetic parameters k, Ks, Y, and kd were 2.52 d-1, 49.68 mg COD/L, 0.25 mg VSS/mg COD, and 0.46 d-1, respectively. The pesticide industry effluent caused a competitive inhibition above a dose of 1.6% on un-acclimated culture. High treatment efficiency can be achieved in aerobic biological treatment when the biomass gets acclimatized to the pesticide industrial effluent. © 2018 American Society of Civil Engineers.